Columns Run Out of Credit: Template Email Column Fully Depleted - Need Assistance

Hey! Today I woke up and the columns were fully run out of credit 😕 There were over 1500 yesterday. I initially thought it was a technical error, to then see a column "Template Email" that was completely run. I don't know what happened, but I don't know that column run, it was a trial column 😕 I am being super careful in using my credits well and we didn't need this thing. Could you please help?